3PAR InForm OS 2.3.1 MU2 Release Note (325-200142 Rev B, October 2010)

2.11
Known Issues with the InForm OS
InForm OS Version 2.3.1 MU2 3PAR InForm OS Release Notes
3PAR Confidential
downgrade, dual SD TPVVs must be converted to single SD TPVVs by removing all of the
snapshots for those TPVVs.
■ Raid Multi-Parity (MP) - Raid MP was not supported in InForm OS releases prior to 2.3.1,
therefore any Raid MP Logical Disks (LDs) must be tuned to a supported RAID type or
removed prior to downgrade.
■ SD Reclaim Space - SD Reclamation is not supported by InForm OS releases prior to 2.3.1.
Before a downgrade, SD volumes that have its space reclaimed must be removed. If that SD
is used by snapshots only, then all of its snapshots must be deleted so that SD can be freed.
If that SD space is used by the TPVV itself, then that TPVV would need to be copied over to
a new single SD TPVV. After the copy operation completed, the original TPVV can be
removed.
■ 256 Read/Write Snapshots - In InForm OS 2.3.1 and 2.3.1 MU2, the number of read/write
snapshots was increased to 256 per virtual volume. Previous release supported a smaller
maximum number of read/write snapshots per virtual volume. A downgrade will be
prevented if any virtual volume has more read/write snapshots than the maximum
supported on the previous release. When enough snapshots have been removed to meet
this criterion the downgrade is allowed.
■ Multiple Read/Write Snapshots per Read-Only Snapshot - In InForm OS 2.3.1 and 2.3.1
MU2, the creation of multiple read/write snapshots per read-only snapshot is permitted.
Previous releases supported a single read/write snapshot per read-only snapshot. A
downgrade will be prevented if any read-only snapshot has more than one read/write
snapshot. Once enough read/write snapshots have been removed to meet this criteria, the
downgrade is allowed.
■ Synchronous Long Distance Remote Copy - If there are Remote Copy groups
configured with multiple targets, those groups must be removed or reduced to a single
target before a downgrade is allowed.
■ 16 TB Support - Virtual volumes larger than the maximum size supported in a previous
release must be removed before a downgrade is allowed.
■ Multiple Remote Copy Links per Node - InForm OS release 2.3.1 and 2.3.1 MU2 allow
multiple Remote Copy links to be configured on a individual node. Previous releases only
allowed a single link per node. Before downgrading, ensure that additional Remote Copy
links are dismissed to ensure a valid configuration for the downgrade. A check is run prior
to downgrade to validate the existing Remote Copy link configuration.